Not enough computer power??

I have a quite "heavy" computer with a lot of power, I think. But at the project I am working now, the computer begins to slow down. The project is two storey + topfloor/roof and now I am working at 1.st floor and finished ground floor. When I choose a function like wall list, to put in post, to cut off timber etc., most of the times I have to wait a long time before the function is available. So half of the time I am working I am waiting.... The project is a big one, but no that big - about 300 m2 in ground floor and in 1st. floor, total 600 m2.

Below you see my computer:

Plus Lite Amitech PL model D865PERLK
BIOS version P19-0085.bio

Varetype Antal Beskrivelse
Strømforsyning 1 Strømforsyning FSP300-60PN(PF)
Kabinet 1 Amitech Midi ATX kabinet sølv
Bundkort 1 Intel D865PERLK ATX bundkort
Processor 1 Intel Pentium 4 3.2GHz HT 800FSB
RAM 1 1GB MB DDR-RAM 400MHz (2*512MB)
RAM 1 1GB MB DDR-RAM 400MHz (2*512MB)
Floppydrev 1 Diskdrev 3.5 1.44MB (sort)
Harddisk 1 36GB 10K WD S-ATA harddisk
Harddisk 1 250GB 7200rpm harddisk
Harddisk 1 250GB 7200rpm harddisk
Grafikkort 1 ATI Radeon 9550 256MB RAM TV-out
Lyd 1 Integreret lydkort
Modem 1 CastleNet SL1900 modem
Netkort 1 Integreret netkort
DVD drev 1 16x DVD drev (sort)
DVD brænder 1 DVD Brænder (-/+R/RW) (sort)
Diverse hardware 1 FireWire kort
Diverse hardware 1 SmartCard reader og 5.25" ramme (sort)
TV/Video kort 1 TV 2000 XP TV/FM PVR kort
Tastatur 1 Amitech trådløs optisk mus/tast 5511 DK
Højttalere 1 Amitech Flad højtt. m/subw. model 200
Operativsys. 1 MS Windows XP Pro DK (CD 21)
Recovery 1 Genindlæsnings CD 21.14 - CD 1
Recovery 1 Genindlæsnings CD 21 - CD 2+3
Software 1 Amitech Bullguard 6 mdr. Antivirus/FW/BU
Software 1 Cyberlink PowerDVD 5.0 licens
Software 1 Sonic RecordNow! v6
Software 1 Amitech værktøjer og opsætning
Brugervejledning 1 Brugervejledning til Amitech PC DK
Service 1 1 års indleveringsservice DK (PC)
Telefonhjælp 1 Telefonhjælp i 3 måneder

Then I cannot undo... But of course it is worth a try to put number of undo steps to 1 or even 0. But when I was working on ground floor there was no problems, but at 1st floor, significant difference.

Ah yes that can be the real answer to why it is is going slowly. I have assisting DXF geometry on both ground floor and 1st floor. So I should just delete them - ah well I am not finished using them... So maybe I should just delete the parts of the geometry that I don't need more.

Yesterday evening I tried first to delete some of the assisting geomtery, but not completely all. There was a change in speed, but after a while I realized that I needed more speed if I did not want to work all night to finish - so I put undo steps to zero - and THAT was a huge difference in speed - almost immediatly response on all my commands!!! I made 66 drawings with my own template, in about two hours - I was working really effective.